SU110870A1 - Spiral drill - Google Patents

Description

Constructions of twist drills with two spiral channels placed in the drill stitches and intended for supplying a cooling lubricant under pressure to the cutting zone are known.

Such a drill design significantly increases the durability and strength of the drills and has a beneficial effect on the cutting process.

However, in spite of the existing advantages, they have not found wide application in industry, since their manufacture presents great technological difficulties, and the designs in some cases do not provide operational reliability.

The described twist drill bit differs from the known ones in that the shape of the cross section of the spiral channels in the feathers is made in the same way as the profile of the feather section. This makes it possible to increase the cross-sectional area and the amount of cooling and lubricant passed through them in a unit of time with equal, compared with the existing hole shapes, wall thickness. In addition, this channel shape greatly expands the range of drill diameters in which cooling channels can be formed. Since the draw ratio of the working part of the drill is more than 2, the sum of the cross sections of the channels of the working part of the drill is always smaller than the cross section of the feed channel of the tail section, which leads to an increase in the flow rate of the coolant into the cutting zone and ensures its penetration between the rubbing surfaces of the workpiece and cutting tools. The centers of the cross sections of the spiral channels are displaced to the periphery and the main cutting edges, which ensures greater strength of the core of the drill and favors the working conditions of those sections that are the most loaded.

FIG. 1 shows a twist drill bit with channels; in fig. 2-view of the drill from the side of the cutting edges; in fig. 3 is the same in cross section.

No. 10870

The twist drill bit consists of two parts: the working part I and the tail part 2, which are made as one piece or joined together by welding.

The working part / is made in the form of two spiral-shaped feathers. Throughout its entire length, spiral channels 3 are located in the perimeter to supply the cooling lubricant under pressure to the cutting zone.

Depending on the method of its fastening on the machine, the tail part 2 is made in the form of a cone or shchindra equipped with a cylindrical axle channel 4, which has a larger diameter than the spiral channels 3 connected with it 3 The profile of the working part / is made without sharp transitions and sharp edges. The rear cutting surface has the output grooves of the spiral channels 3. The cross section of the channels 3 has a profile similar (equidistant) to the profile of a feather. This form of section is the most optimal, since it allows for equal, compared to existing forms of holes, wall thickness to increase the cross-sectional area and the amount of material passed through them per unit time. This contributes to a more efficient cooling and reliable removal of chips from the hole and increase productivity in drilling. In addition, the selected hole pattern significantly clears the range of drill diameters in which cooling channels can be formed.

The centers of the sections of the channels C1 are shifted to the periphery and the main cutting edges, which provides greater strength of the core of the drill and favors the working conditions of those edge sections that are the most loaded and limit the cutting process. In this case, the sum of the areas of the cross sections of the channels of the working part of the drill should always be less than the cross section area of the feed channel of the tail section, which leads to an increase in the flow rate of the coolant into the cutting zone and ensures its penetration between the rubbing surfaces of the workpiece and the cutting tool, reduces wear and allows Does not work at higher cutting conditions.

Such a drill design makes it possible to increase the productivity of the drilling process by a factor of 2, or increase the drill resistance by up to 24 times.

Subject invention

Claims (2)

I- A twist drill with two spiral channels in the drill bits for supplying a cutting lubricant under pressure to the cutting zone, connected to an inlet channel, characterized in that, in order to increase the range of drill diameters with channels due to small-diameter drills, the capacity of the channels without violating the strength of the walls of the feathers, it is made with a cross section of spiral channels with a similar (equidistant) profile of the cross section of the pen. 2. The form of the drill according to claim 1, characterized in that, in order to increase the intensity of cooling of the most loaded areas of the cutting edges and increase the strength of the core of the drill, the centers of the cross sections of the spiral channels are made offset to the periphery of the drill and to the main cutting edges.